How Robotic Surgery Works


Future advances in robotic surgery will include wireless control without time lag, sense of touch, voice commands and integration with magnetic resonance imaging.

Robotic surgery involves the use of remote controlled, precision instruments to replace a surgeon’s hands and conventional tools. Robotic surgery is a reality today and already enhances the abilities of a conventional surgeon. A robotic surgeon sits at a console a few feet away from the patient and controls the robotic surgical instruments through joysticks. Incisions in robotic surgery are small, precise and very steady. This means less bleeding and trauma, reduced chances of infection and quicker patient recovery. Errors because of surgeon fatigue are eliminated. A major application is in cardiac surgery. Robotics makes it possible to work on the heart while it continues to beat. Conventional surgery requires the heart to be stopped while it is repaired.

Robotic surgery has a long way to go and research is in progress to remove its handicaps. A major issue is that the surgeon has still to be in the vicinity of the patient. Robotic instruments can be controlled over long distances through optic fiber cables. However, the time lag in such a system between the robotic surgeon giving a command through a joystick and the action of the robot can be significant and may harm the patient. Loss of power as in an electrical failure is a related concern. The development of wireless commands for robots will remove these bottlenecks and make it reasonably safe for robotic surgeons to operate over vast distances. Robotic surgery will be possible across nations, deep under the sea and in outer space. Such robotic surgery through real-time, wireless controls will need the presence of especially trained personnel near the patient, who can take over in an emergency and who can help the surgeon at the remote location. Remote surgery through robotics has legal and ethical issues that have to be resolved before the technology is put to work.

Robotic surgery works through the sense of vision. A robotic surgeon has the advantage of magnified vision enabling sight of things out of reach of the human eye. However, surgeons also rely on the sense of touch. Robotic surgery in future will include sensors to enable a surgeon feel the strength and nature of the tissue being manipulated and cut.

Robotic surgery has been developed independently of imaging technologies based on magnetic resonance. The latter makes it possible to look inside a body without cutting it open. It also extends the range of human vision to chemical processes within the body. Work is in progress to merge the technology of robotics with that of imaging so that it will be possible to detect malfunctions within the body and to correct them in time, in a manner that is significantly better than at present.

Conventional surgery requires a rather large team of people. Some hold instruments, others manipulate the body and still others control lights and ventilation inside the operation theater. Robotic surgery with voice commands will enable surgeons to do their work with fewer assistants. They will be able to change and to control conditions directly at the same time as they work the joysticks.

Robots will not replace human intelligence, skill and experience in the foreseeable future. They will however significantly extend human ability and robotic surgery will continue to advance frontiers of medical science.


CURRENT ROBOTIC SURGICAL SYSTEMS


Today, many robots and robot enhancements are being researched and developed. Schurr et al at Eberhard Karls University’s section for minimally invasive surgery have developed a master-slave manipulator system that they call ARTEMIS.13 This system consists of 2 robotic arms that are controlled by a surgeon at a control console. Dario et al at the MiTech laboratory of Scuola Superiore Sant’Anna in Italy have developed a prototype miniature robotic system for computer-enhanced colonoscopy.14 This system provides the same functions as conventional colonoscopy systems but it does so with an inchworm-like locomotion using vacuum suction. By allowing the endoscopist to teleoperate or directly supervise this endoscope and with the functional integration of endoscopic tools, they believe this system is not only feasible but may expand the applications of endoluminal diagnosis and surgery. Several other laboratories, including the authors’, are designing and developing systems and models for reality-based haptic feedback in minimally invasive surgery and also combining visual servoing with haptic feedback for robot-assisted surgery.15–19

In addition to Prodoc, ROBODOC and the systems mentioned above several other robotic systems have been commercially developed and approved by the FDA for general surgical use. These include the AESOP system (Computer Motion Inc., Santa Barbara, CA), a voice-activated robotic endoscope, and the comprehensive master-slave surgical robotic systems, Da Vinci (Intuitive Surgical Inc., Mountain View, CA) and Zeus (Computer Motion Inc., Santa Barbara, CA).

The da Vinci and Zeus systems are similar in their capabilities but different in their approaches to robotic surgery. Both systems are comprehensive master-slave surgical robots with multiple arms operated remotely from a console with video assisted visualization and computer enhancement. In the da Vinci system (Fig. 1) , which evolved from the telepresence machines developed for NASA and the US Army, there are essentially 3 components: a vision cart that holds a dual light source and dual 3-chip cameras, a master console where the operating surgeon sits, and a moveable cart, where 2 instrument arms and the camera arm are mounted.1 The camera arm contains dual cameras and the image generated is 3-dimensional. The master console consists of an image processing computer that generates a true 3-dimensional image with depth of field; the view port where the surgeon views the image; foot pedals to control electrocautery, camera focus, instrument/camera arm clutches, and master control grips that drive the servant robotic arms at the patient’s side.6 The instruments are cable driven and provide 7 degrees of freedom. This system displays its 3-dimensional image above the hands of the surgeon so that it gives the surgeon the illusion that the tips of the instruments are an extension of the control grips, thus giving the impression of being at the surgical site.

da+vinci+system+set-up.jpg
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FIGURE 1. Da Vinci system set up. (Courtesy of Intuitive Surgical Inc., Mountain View, CA)

The Zeus system is composed of a surgeon control console and 3 table-mounted robotic arms (Fig. 2) . The right and left robotic arms replicate the arms of the surgeon, and the third arm is an AESOP voice-controlled robotic endoscope for visualization. In the Zeus system, the surgeon is seated comfortably upright with the video monitor and instrument handles positioned ergonomically to maximize dexterity and allow complete visualization of the OR environment. The system uses both straight shafted endoscopic instruments similar to conventional endoscopic instruments and jointed instruments with articulating end-effectors and 7 degrees of freedom.

zeus+system+set-up.jpg
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FIGURE 2. Zeus system set up. (Courtesy of Computer Motion Inc., Santa Barbara, CA)

Development and in vitro testing of a miniature robotic system for computer-assisted colonoscopy.
Comput Aided Surg. 1999; 4(1):1-14.
[Comput Aided Surg. 1999]
Surgical robotics: the early chronicles: a personal historical perspective.
Surg Laparosc Endosc Percutan Tech. 2002 Feb; 12(1):6-16.
[Surg Laparosc Endosc Percutan Tech. 2002]
Robotics and telemanipulation technologies for endoscopic surgery. A review of the ARTEMIS project. Advanced Robotic Telemanipulator for Minimally Invasive Surgery.
Surg Endosc. 2000 Apr; 14(4):375-81.
[Surg Endosc. 2000]



Supervisory-controlled Robotic Surgery Systems

Of the three kinds of robotic surgery, supervisory-controlled systems are the most automated. But that doesn't mean these robots can perform surgery without any human guidance. In fact, surgeons must do extensive prep work with surgery patients before the robot can operate.

Spencer Platt/Getty Images
Dr. Scott J. Boley demonstrates a robotic surgery system
at the Montefiore Institute for Minimally Invasive Surgery
in New York City.


That's because supervisory-controlled systems follow a specific set of instructions when performing a surgery. The human surgeon must input data into the robot, which then initiates a series of controlled motions and completes the surgery. There's no room for error -- these robots can't make adjustments in real time if something goes wrong. Surgeons must watch over the robot's actions and be ready to intervene if something doesn't go as planned.

What's Up, RoboDoc?
The RoboDoc system from Integrated Surgical Systems is an example of a supervisory-controlled system used in orthopedic surgeries. Once a human surgeon positions the RoboDoc's bone-milling tool at the correct location inside the patient, the robot takes over. It automatically cuts the bone to just the right size for the orthopedic implant.

The reason surgeons might want to use such a system is that they can be very precise, which in turn can mean reduced trauma for the patient and a shorter recovery period. One common use for these robots is in hip and knee replacement­ procedures. The robot's job is to drill existing bone so that an implant fits snugly into the new joint.
Because no two people have the exact same body structure, it's impossible to have a standard program for the robot to follow. That means surgeons must map the patient's body thoroughly so that the robot moves in the right way. They do this in a three-step process called planning, registration and navigation [source: Brown University].
In the planning stage, surgeons take images of the patient's body to determine the right surgical approach. Common imaging methods include computer tomography (CT) scans, magnetic resonance imaging (MRI) scans, ultrasonography, fluoroscopy and X-ray scans. For some procedures, surgeons may have to place pins into the bones of the patient to act as markers or navigation points for the computer. Once the surgeon has imaged the patient, he or she must determine the surgical pathway the robot will take.
The surgeon must tell the robot what the proper surgical pathway is. The robot can't make these decisions on its own. Once the surgeon programs the robot, it can follow instructions exactly.
The next step is registration. In this phase, the surgeon finds the points on the patient's body that correspond to the images created during the planning phase. The surgeon must match the points exactly in order for the robot to complete the surgery without error.
The final phase is navigation. This involves the actual surgery. The surgeon must first position the robot and the patient so that every movement the robot makes corresponds with the information in its programmed path. Once everyone is ready, the surgeon activates the robot, which carries out its instructions.
­The next type of robot can only act under the direction of a human surgeon. Let's go to the next section and learn about the da Vinci Surgical System.


Robotic Surgery in Cardiology (F:\Robotic Surgery, Organ Systems, Cardiology_files\index.htm)

Introduction

With the rapid advancement of technology, cardiac surgery is also entering a revolution in methodology and healthcare. Over time, technology has evolved to improve the way that these surgeries are conducted. In the case of Coronary Artery Bypass Grafting (CABG), many surgeons are slowly switching to Off-Pump Coronary Artery Bypass Surgery (OPCAB), where bypasses are performed without the use of the heart-lung machine. However, the patient's chest is still opened and to reveal the heart which leads to a relatively long recovery time. Recently, many coronary artery problems have increasingly been treated by angioplasty, which is a minimally invasive procedure. During these surgeries, rather than bypassing the occluded artery, patients are outfitted with stents that forcefully push the artery open, allowing blood to flow through the once-blocked arteries. Angioplasties can't be performed on all patients with coronary artery disease, and other options like CABG or OPCAB are needed. With those options, came the downside of having open chest surgery, until now. With the introduction of robotics into this field of medicine, surgeons have been able to replace sternotomy and thoracotomy with small incision entries. As a result, there has been decreases in patient trauma and morbidity. Most initial robotic procedures were limited to harvesting veins and arteries for grafts. However, with advents such as the da Vinci Surgical System, the role of robotics in cardiac surgery is becoming more useful.
Science and Technology
The entry of robotics into the field of cardiology has been a gradual scaled process that can be broken down into four levels: Direct Vision and Mini-Incisions (Level 1), Video-Assisted and Micro-Incisions (Level 2), Video-Directed and Port Incisions (Level 3), Video-Directed and Robotic Instruments (Level 4). Each level increases in complexity and robotic involvement.
Level 1 Direct Vision and Mini-Incisions:
This level encompasses conventional minimally invasive surgery. Using, mini-sternotomies, parasternal incisions, and mini-thoracotomies, the first minimally invasive aortic valve operations were performed through this conventional tactic1. However, this technique in cardiac surgery proved that operations could be performed through smaller incisions and therefore, acted as a springboard to the next level.
Level 2 Video-assisted and Micro-Incisions:
Though now videoscopy could by used to enlarge the vision of the surgical field, the benefits were limited to simple repairs and replacement. Complex repairs, such as quadrangular resections and chordal replacements, were performed with few complications2. Nonetheless, surgeons still awaited 3D imaging and robotic instruments.
Level 3 Video-Directed and Port Incisions:
Imaging modalities such as CT scans have contributed greatly to the planning and registration of procedures. This stage saw the first integration of a robotic arm in carrying out procedures. In addition to the robotic arm, surgeons used an endoscope and a conventional two-dimensional monitor to view the procedure. Devices such as Aesop enabled surgeons to increase precision and control for hand tremors through robotic actions triggered by voice-activated commands. Though the complexity of the devices cannot be compared to the Level 4 technology, these endoscopic techniques allows a wide range of minimally invasive surgery.
Level 4 Video-Directed and Robotic Instruments:
Current cardiac surgery involves the use of complex 3-D imaging techniques and robotic devices. Though just a few years ago Computer Intuitive's Zeus Surgical System was the leading device in cardiac surgery, the economic landscape has changed and now Intuitive Surgical's da Vinci Surgical Device dominates the area of robotics in cardiac surgery.
DIGITAL SURGERY
System Overview
*
Making a one-centimeter keyhole incision to perform the operation, the surgeon is able to engage in minimally invasive surgery through this system. According to Ben Gong, Intuitive Surgical's vice president of finance, da Vinci reduces the average 2-3% infection probability to nearly zero2. There are four main components to da Vinci: the surgeon console, patient-side cart,
EndoWrist Instruments, and Insite Vision System with high resolution 3D Endoscope and Image Processing Equipment.

1. Surgeon Console
The surgeon is situated at this console several feet away from the patient operating table. The surgeon has his head tilted forward and his hands inside the system’s master interface. The surgeon sits viewing a magnified three- dimensional image of the surgical field with a real-time progression of the instruments as he operates. The instrument controls enable the surgeon to move within a one cubic foot area of workspace.


2. Patient-side Cart
This component of the system contains the robotic arms that directly contact the patient. It consists of two or three instrument arms and one endoscope arm. The feedback as of today is limited to sensing tool-on-tool collision, so the surgeon needs to rely almost solely on the visual field when suturing or contacting soft tissue. As of 2003, Intuitive launched a fourth arm, costing $175,000, as a part of a new system installation or as an upgrade to an existing unit2. It provides the advantages of being able to manipulate another instrument for complex procedures and removes the need for one operating room nurse3.


3. Detachable Instruments
(Endowrist® Instruments and Intuitive® Masters)
The Endowrist detachable instruments allow the robotic arms to maneuver in ways that simulate fine human movements. Each instrument has its own function from suturing to clamping, and is switched from one to the other using quick-release levers on each robotic arm. The device memorizes the position of the robotic arm before the instrument is replaced so that the second one can be reset to the exact same position as the first. The instruments’ abilities to rotate in full circles provide an advantage over non-robotic arms. The seven degrees of freedom (meaning the number of independent movements the robot can perform) offers considerable choice in rotation and pivoting4. Moreover, the surgeon is also able to control the amount of force applied, which varies from a fraction of an ounce to several pounds. The Intuitive Masters technology also has the ability to filter out hand tremors and scale movements. As a result, the surgeon’s large hand movements can be translated into smaller ones by the robotic device5. Carbon dioxide is usually pumped into the body cavity to make more room for the robotic arms to maneuver.



4. 3-D Vision System
(Insite® Vision and Navigator Camera Control)
The camera unit or endoscope arm provides enhanced three-dimensional images. This high-resolution real-time magnification showing the inside the patient allows the surgeon to have a considerable advantage over regular surgery. The system provides over a thousand frames of the instrument position per second and filters each image through a video processor that eliminates background noise. The endoscope is programmed to regulate the temperature of the endoscope tip automatically to prevent fogging during the operation3. Unlike The Navigator Control, it also enables the surgeon to quickly switch views through the use of a simple foot pedal.
Percutaneous Renal Access is through the skin renal access. A large part of thie procedure is based on the surgeoun’s experience and technique.
1. NeuroArm (2006 – University of Calgary, Calgary, Alberta, Canada)
Although there are robotic systems that can perform specific well-defined tasks, there is currently no system that can perform a whole range of neurosurgical procedures. The $30 million NeuroArm project packages all the features that a neurosurgeon would need to directly manipulate any intra-cranial function (given present day technical constraints)4. Designed based on biomimicry, the controller’s hand movements (master) are replicated by robotic arms (slave) which hold surgical tools. The NeuroArm comprises 2 arms, each with 7 degrees of freedom, and a third arm with 2 cameras which provides the surgeon with a 3-D stereoscopic view7. NeuroArm is able to carry out microsurgical techniques and soft tissue manipulations such as biopsy, microdissection, thermocoagulation, blunt dissection, grasping of tissue, cauterizing, manipulation of a retractor, tool cleaning, fine suturing, suction, microscissors, needle drivers, and bipolar forceps. All the tools are exchanged at the end-effector, which also provides haptic force feedback to the surgeon. The 3rd component of the NeuroArm which makes it unique is the workstation7. In an attempt to replicate the surgical arena, the workstation provides the surgeon with 3 areas of feedback: sound, sight, and touch4. The surgical microscope (binoculars) give stereoscopic views of the brain’s complex folds, while MRIs and robotic sensors create a 3-dimensional map of the brain for the surgeon on the displays. The microsurgical tools and real-time MRIs increase the accuracy of the surgeon 1000-folds (from an accuracy level of 1 millimeter to one-thousandth of a millimeter)5. The NeuroArm also incorporates safety features such as filtering out hand tremors, fail safe switches that prevent accidental movements, and force sensors which provide the sense of touch4,5. With a combination of intraoperative MRIs and fiducial markers, the neuroArm can also program the boundaries of the surgical field during presurgical planning. This is a safety feature against accidental movements. The materials used to build the components have been thoroughly tested for MR compatibility. The robotic arms are made out of titanium and polyetheretherketone (plastic polymer) because they have the least image distortion. The NeuroArm’s image guidance system is so advanced that the surgeon can simulate the procedure in virtual reality beforehand. NeuroArm is currently being manufactured after going through a lengthy testing stage, and should be available in clinics within 2 years5.



The workstation includes a computer processor, hand controllers for robotic arms, joystick controller for cameras and lights, 3 different displays and recorders7.
o Video Display presents a 3-D stereoscopic view to give surgeon sense of depth.
o MR Display shows the patients MR scan and tracks the location of the tool in real-time (pre, post, and intraoperative).
o Control Panel Display shows operation status, force feedback, and control configuration.



Robotic Long-Distance Telementoring in Neurosurgery8
Telementoring and Telesurgery (The Socrates System)
Advancements in computer and telecommunication technology have made it possible for a skilled surgeon to provide real-time guidance to less skilled surgeons across the country. Neurosurgery is ideal for telementoring and telesurgery because of the fact that neurosurgical institutions are usually confined to large urban areas. The Socrates system was the first telecollaboration system to be approved by the FDA, and was first used in Canada when a neurosurgical center in Halifax, Nova Scotia telementored a smaller center in Saint John, New Brunswick. Using the Socrates system, the mentor had direct control of the endoscope camera, real-time neuronavigation data, and two-way video and audio communications with the operative site. He was even able to control the robotic arm, AESOP, if necessary to give him full control of the surgical field in the remote site. It is called telementoring when the local surgical team is performing the operation with an expert mentor watching through the interface for errors. It is called telesurgery when the mentor performs the surgery directly with a surgical team watching to learn techniques (and as a safety precaution should mechanisms fail). Although the mentors have full control of the robotic arm’s movements during telesurgery, the surgeons in the remote area could override the mentor’s control as a safety feature. The general conclusions from the 6 patient trials in Canada was that advice from an expert neurosurgeon provides significant advantages, and that neurosurgeons could save a lot of traveling time. However, experts are debating whether the high costs of skilled neurosurgeons are worth the marginal benefits. Furthermore, liability issues when telecollaboration is performed across the boarders of states and countries have hindered the expansion of this service8.


Robotic Long-Distance Telementoring in Neurosurgery8
3. Artificial Intelligence and Artificial Thought Processing
With improvements in artificial intelligence, the robot will be able to sense what the surgeon is thinking and provide the appropriate responses. Furthermore, expert computer systems can replicate certain human functions, such as diagnosis of the human illness2.
With advances in kinesthesia and quantitative reasoning, the robot should be able to understand the complex 3-D arena, and be able to plan the intraoperative procedure for the surgeon.

4. Surgical Simulation and Virtual Reality (Interactive Virtual Dissection)
Neurosurgeons have to be incredibly precise and knowledgeable when dealing with the highly complex cranial anatomy. By simulating an operation in an interactive 3-D environment, surgeons can practice over and over again to perfect their technique in a safe environment by manipulating 3-D models, and study the structures from many perspectives9,10. A project entitled interactive virtual dissection (IVD) attempts to simulate the drilling of the petrous bone in a virtual environment that provides the surgeon with visual, audio, and tactile feedback9.


3-D Interactive Virtual Dissection Model
The creation of the IVD simulation involved 4 main steps:

    1. Data generation from cadaver dissections
    2. Data collection from stereoscope, MRI, image rendering
    3. Image reconstruction and merging to create a 3-D model
    4. A virtual reality system that uses the 3-D model and can recreate the dynamics of the cranial anatomy
The perfect simulator would be able to create a virtual environment that is indistinguishable from real-life experience by providing sensory input to all of our senses. However, the current virtual surgical simulators have many limitations, as it is unable to provide real-time haptic feedback and unable to recreate the physics of tissue displacement3,9,10. Without tactile feedback, the surgeon would not be accurately and safety performing the operation, and it simply would not feel like they are in the operating room. With technological advancements in the future, simulated surgical training environments should become increasingly lifelike. It should soon become an effective educational tool for neurosurgery, as it is less expensive than cadavers, and it permits performance evaluation of residence students as patients do not want them performing any major role in the operation9,10.

Virtual Reality Neurosurgery10 Before this becomes an effective form of training and surgeon evaluation, it will need to show that a more structured curriculum and usage of the simulator will improve operating room results. As more detailed data becomes available with increasing number of operations, patient-specific simulation can be done by importing their MRIs2,3,9,10.

ii. Telesurgery, Telemedicine, Telementoring

F:\Robotic Surgery, Organ Systems, Urology_files\index.htm

Remote controlled instrumentation and Munich operating room in telesurgery case (http://pegasus.me.jhu.edu/~rwebster/index_files/pub_files/chapter.pdf)

Telesurgery is an integration of multimedia, telecommunications and robotic technologies that provide surgery at a distance6. Telesurgery in urology is being evaluated with more advances in technology7. Telemedicine is the exchange of real time data of medical information between physicians in different locations. Telementoring is the assistance of an experienced surgeon in a remote operation4. An experienced surgeon at a remote site can teleoperate the robotic arm and guide the primary surgeon through a procedure. This would be an education device to convey the expertise and experience of a an adept surgeon to second surgeon at a different location. The system as of 1999 incorporates bidirectional video and audio communication, telestration, electroautery remote activation to stop blood vessels from bleeding, x-ray image transfer and remote control of AESOP robot.7.
For laparoscopic procedures in particular there have been three generations of laparoscopic telesurgery. The first operated remotely within the same hospital. The second moved the remote site to a different institution of about 3.5 miles away. The third generation involved laparoscopic telesurgery in an international level in which pr ocedures were done in Thailand, Austria, Italy, and Singapore. Telementoring used for an education purpose was done between Singapore and the United States.7.
Developments in telecommunications and computer technology is improving and developing the application of telesurgical, telemedicinal, and telementoring devices

Resources: F:\Robotic Surgery, Da Vinci Surgical System_files\index.htm
F:\Robotic Surgery, History_files\index.htm

F:\Robotic Surgery, Organ Systems, Urology_files\index.htm